Tailgate spontaneously opening

[HDroofer]

Knock on wood I have also not had this issue on my 22 lt w/ multi-flex.  My truck lives outside in snow, rain, and gets washed frequently.  Hoping this never does happen and would like to kno what the definitive reason is behind it and the fix to go along with it

[4x4Hank]

Well, chalk up another inner tailgate switch. I started to head out this morning and my dash said “Inner Tailgate Open.” So I checked and it wasn’t open nor was it even unlatched. I tried to open it but the switch was not working. The main tailgate switch worked fine. Whenever I tried the inner tailgate the taillights would blink three times. I started the truck up and the flashers would blink three times, stop, and then blink again. I opened and closed the main tailgate several times to see if that would clear it but it didn’t help. The lights quit flashing eventually and they also quit flashing when I pressed the inner tailgate switch. But the switch never worked again, not that I expected it to after that. Truthfully I have lost count now as to how many switches have been replaced. I do know that most of them have been the inner tailgate switch. 
Late yesterday, I had the truck bed loaded with firewood so when I was done unloading I hosed the bed out. I’m even more certain than before that water intrusion is the culprit. Why water doesn’t have that same effect on everyone’s truck I have no idea. Back to the GMC dealer on Monday. This is getting real old!

[mtbadbob]

You have to have another wiring issue. There is no way you have that bad of luck with those switches. We've had the wettest year in a long time here, along with me going through high pressure car washes on a regular bases, and I've had zero issues. I'm absolutely sure our tailgates & switch configurations are identical. I'd definitely be looking elsewhere for the problem & solution. If you hold the inner tailgate switch down for 3 seconds, it'll lock it so it won't open it, making your lights flash. That is for when you have a stinger in your receiver hitch. GM put the sticker on the drivers side inside the jamb of the tailgate that shows how the lock works. It sounds like you just have yours locked, try holding it in for 3 seconds & it'll unlock it.

Edited October 8, 2023 by mtbadbob

[4x4Hank]

10 hours ago, mtbadbob said:

You have to have another wiring issue. There is no way you have that bad of luck with those switches. We've had the wettest year in a long time here, along with me going through high pressure car washes on a regular bases, and I've had zero issues. I'm absolutely sure our tailgates & switch configurations are identical. I'd definitely be looking elsewhere for the problem & solution. If you hold the inner tailgate switch down for 3 seconds, it'll lock it so it won't open it, making your lights flash. That is for when you have a stinger in your receiver hitch. GM put the sticker on the drivers side inside the jamb of the tailgate that shows how the lock works. It sounds like you just have yours locked, try holding it in for 3 seconds & it'll unlock it.

Yes, I’m aware of the lockout feature for the inner tailgate. Actually I thought that it was 5 seconds but either way it’s not that. I’ve used that before when I had a bumper pull trailer last year but I switched to a fifth wheel this year so I haven’t had to lock out that feature. It could be another wiring issue however when at the dealer they replace the switch and it will then work for a while anyway. If it’s a wiring issue shorting out the switch wouldn’t it blow a fuse first? It doesn’t seem coincidental that after I hosed out the bed of the truck and the tailgate that I had the switch go bad the very next morning. I have an appointment tomorrow so I’ll ask the technician if he thinks that the problem could be up the line and not the switch itself. The entire problem doesn’t make sense however there is a TSB on the switches getting wet. 

[4x4Hank]

On 10/8/2023 at 10:39 AM, mtbadbob said:

You have to have another wiring issue. There is no way you have that bad of luck with those switches. We've had the wettest year in a long time here, along with me going through high pressure car washes on a regular bases, and I've had zero issues. I'm absolutely sure our tailgates & switch configurations are identical. I'd definitely be looking elsewhere for the problem & solution. If you hold the inner tailgate switch down for 3 seconds, it'll lock it so it won't open it, making your lights flash. That is for when you have a stinger in your receiver hitch. GM put the sticker on the drivers side inside the jamb of the tailgate that shows how the lock works. It sounds like you just have yours locked, try holding it in for 3 seconds & it'll unlock it.

On the way to the dealership this morning I was sitting parked inside the truck and the flashers would blink 3 times real fast and stop. 10 seconds later it would do it again. This simulates the 3 fast blinks on the taillights that happens when the inner tailgate lockout is activated. 
When I got to the dealer the inner tailgate switch was working! 
The dealer checked the Body Control Module and evidently it threw a code. They reprogrammed the BCM. So far so good. 
 

Edited October 9, 2023 by 4x4Hank

[mtbadbob]

Wow, some crazy stuff going on there! Well, maybe that BCM was the issue, hopefully, huh?

[4x4Hank]

8 hours ago, mtbadbob said:

Wow, some crazy stuff going on there! Well, maybe that BCM was the issue, hopefully, huh?

Hopefully 

[jsward12]

Finally! https://www.freep.com/story/money/cars/general-motors/2024/02/06/gm-general-motors-recall-heavy-duty-pickup-trucks-tailgates/72491550007/

[Pryme]

On 2/6/2024 at 2:14 PM, jsward12 said:

Finally! https://www.freep.com/story/money/cars/general-motors/2024/02/06/gm-general-motors-recall-heavy-duty-pickup-trucks-tailgates/72491550007/

Well well I wonder how an electronic switch could possibly short circuit? Maybe water intrusion? 

[SoCal Angler]

The TSB speaks of replacing two parts.  The Recall speaks of replacing the touchpad...are the switches and touchpad one in the same (one part)?

 

Also, how is there a stop sale on all of the new trucks when they had the new parts since July 2023 (TSB)?

 

TSB 23-NA-112

 

Recall

 

BTW...are there two threads on this same topic or is my mind playing tricks on me again!

[mtbadbob]

Well, it's very odd that a few people have had to replace several switches, when others have had zero issues. I'm still not convinced water is the culprit as my truck(s) have gotten plenty wet several times. I'm more convinced that a BCM or other electronic system glitches is the real cause, like just plain cheap Chinese parts. I've seen several cameras fail also, just because of their quality. Did "Slathering" on the silicone resolve anyone's issues???

[4x4Hank]

5 hours ago, mtbadbob said:

Well, it's very odd that a few people have had to replace several switches, when others have had zero issues. I'm still not convinced water is the culprit as my truck(s) have gotten plenty wet several times. I'm more convinced that a BCM or other electronic system glitches is the real cause, like just plain cheap Chinese parts. I've seen several cameras fail also, just because of their quality. Did "Slathering" on the silicone resolve anyone's issues???

I’m not sure what I think the cause is. My fob started acting up sporadically (and yes, I tried new batteries). Both on locking/unlocking and with the ignition. I took it in today thinking that maybe the BCM was also the cause of that (in addition to a previous BCM problem with the tailgate). Diagnosis was faulty fob and they ordered me a new one. 
I did silicone (a couple of neat inconspicuous dabs-no slathering) my tailgate grab handle drain holes long ago. It didn’t help. I’ve posted that I lost track of how many switches I have had replaced, mostly inner tailgate. The recall does not have a remedy as of 2/9/24 but I read that there is a stop order on all new sales so I suspect that a fix shouldn’t be too far off since GM no doubt doesn’t like to see zero sales of a high profit vehicle. 
Hank